Motor unit

ABSTRACT

A motor unit including a motor having a rotor rotatable about a motor axis and a stator radially outside the rotor; a housing having a motor housing portion housing the motor; and a refrigerant channel passing through the interior of the housing. A core back portion of the stator has a plurality of fixing portions projecting radially outward from an outer peripheral surface and extending along an axial direction. An upper fixing portion projecting upward from the outer peripheral surface of the core back portion. The refrigerant channel includes a supply portion for feeding refrigerant to the outer peripheral surface of the core back portion. The supply portion is on a side portion of the upper fixing portion in a circumferential direction. The housing includes a breather portion above the upper fixing portion and allows communication between the interior of the motor housing portion and the outside.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is the U.S. national stage of application No. PCT/JP2020/000652,filed on Jan. 10, 2020 and priority under 35 U.S.C. § 119(a) and 35U.S.C. § 365(b) is claimed from Japanese Patent Application No.2019-040863, filed on Mar. 6, 2019, Japanese Patent Application No.2019-075237, filed on Apr. 11, 2019, and Japanese Patent Application No.2019-110648, filed on Jun. 13, 2019; the disclosures of which areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a motor unit.

BACKGROUND

In a motor unit including a motor and a gear portion, a structureincluding a breather mechanism for adjusting pressure in a motor housingis known. There is a motor case in which a communicating path leading toa motor chamber is provided in a channel leading from a gear chamber toa breather mechanism. According to such a configuration, it is possibleto suppress hydraulic oil from leaking from a breather device.

In the conventional structure, however, suppression of leakage in a casewhere a vehicle travels on a slope or the like is not sufficientlyconsidered, and thus, there is a possibility that oil leaks from abreather portion.

SUMMARY

One aspect of a motor unit of the present invention includes: a motorhaving a rotor that rotates about a motor axis and a stator locatedradially outside the rotor; a housing having a motor housing portionthat houses the motor; and a refrigerant channel that is arranged topass through the interior of the housing and circulate a refrigerant. Acore back portion of the stator has a plurality of fixing portions thatare arranged to project radially outward from an outer peripheralsurface and extend along an axial direction, and are fixed to thehousing. The plurality of fixing portions include an upper fixingportion arranged to project upward from the outer peripheral surface ofthe core back portion. The refrigerant channel includes a supply portionthat feeds the refrigerant to the outer peripheral surface of the coreback portion. The supply portion is located on a side portion of theupper fixing portion in a circumferential direction. The housing isprovided with a breather portion that is located above the upper fixingportion and allows the interior of the motor housing portion and theoutside of the housing to communicate.

The above and other elements, features, steps, characteristics andadvantages of the present disclosure will become more apparent from thefollowing detailed description of the preferred embodiments withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptual configuration diagram schematically illustratinga motor unit according to one embodiment;

FIG. 2 is a perspective view illustrating a stator and a supply pipeunit according to one embodiment;

FIG. 3 is a partial cross-sectional view of a motor unit 1 according toone embodiment; and

FIG. 4 is a top view illustrating the stator and the supply pipe unitaccording to one embodiment.

DETAILED DESCRIPTION

In the following description, a description will be given by defining avertical direction based on a positional relationship when a motor unit1 according to an embodiment of the invention is mounted on a vehicle(not illustrated) located on a horizontal road surface. In addition, inthe drawings, an xyz coordinate system is shown appropriately as athree-dimensional orthogonal coordinate system. In the xyz coordinatesystem, a z-axis direction corresponds to the vertical direction. A +zside corresponds to an upper side in the vertical direction, while a −zside corresponds to a lower side in the vertical direction. In thepresent embodiment, the upper side in the vertical direction and thelower side in the vertical direction will be referred to simply as the“upper side” and the “lower side”, respectively. An x-axis direction isa direction orthogonal to the z-axis direction and is a front-reardirection of the vehicle on which the motor unit 1 is mounted. In thepresent embodiment, a +x side is a front side of the vehicle, and a −xside is a rear side of the vehicle. A y-axis direction corresponds to aleft-right direction of the vehicle, i.e., a width direction of thevehicle, and is a direction perpendicular to both the x-axis directionand the z-axis direction. In the present embodiment, a +y side is a leftside of the vehicle, and a −y side is a right side of the vehicle. They-axis direction corresponds to an axial direction of a motor axis J1 tobe described later. Each of the front-rear direction and the left-rightdirection is a horizontal direction perpendicular to the verticaldirection. In the present embodiment, the left side corresponds to oneside in an axial direction, and the right side corresponds to the otherside in the axial direction. In addition, the front side corresponds toone side in the horizontal direction, and the rear side corresponds tothe other side in the horizontal direction.

Note that the positional relationship in the front-rear direction is notlimited to the positional relationship in the present embodiment, andthe +x side may be the rear side of the vehicle, and the −x side may bethe front side of the vehicle. In this case, the +y side corresponds tothe right side of the vehicle, while the −y side corresponds to the leftside of the vehicle.

The motor axis J1 illustrated appropriately in the drawings extends inthe y-axis direction, i.e., the left-right direction of the vehicle. Inthe present embodiment, a direction parallel to the motor axis J1 issimply referred to as the “axial direction”, a radial direction havingits center on the motor axis J1 is simply referred to as the “radialdirection”, and a circumferential direction having its center on themotor axis J1, that is, the axial circumference of the motor axis J1, issimply referred to as the “circumferential direction” unless otherwisenoted. In the present embodiment, one side in the axial direction((i.e., +y side) is a direction from a motor housing portion 61 to agear housing portion 62 of a housing 6, which will be described later,in the axial direction. The other side in the axial direction (i.e., −yside) is a direction from the gear housing portion 62 to the motorhousing portion 61 in the axial direction. Note that, in the presentembodiment, the “parallel direction” also includes a substantiallyparallel direction, and the “perpendicular direction” also includes asubstantially perpendicular direction.

FIG. 1 is a conceptual diagram schematically illustrating the motor unit1. The motor unit 1 of the present embodiment is mounted on a vehicleusing a motor as a motive power source, such as a hybrid electricvehicle (HEV), a plug-in hybrid vehicle (PHV), and an electric vehicle(EV), and is used as the motive power source.

The motor unit 1 includes a motor 2, a gear portion 3 including areduction gear 4 and a differential 5, the housing 6, and an oil passage(refrigerant channel) 90. The oil passage 90 includes a pump 96, acooler 97, a first supply pipe (supply portion) 11, and a second supplypipe (supply portion) 12. Note that the first supply pipe 11 and thesecond supply pipe 12 form a part of a supply pipe unit 10.

The housing 6 includes the motor housing portion 61 that houses themotor 2, the gear housing portion 62 that houses the gear portion 3, apartition 61 c that partitions the interior of the motor housing portion61 and the interior of the gear housing portion 62 in the axialdirection, and a breather portion 70. The gear housing portion 62 isarranged to the left side ((i.e., +y side) of the motor housing portion61. A bottom portion 61 s of the motor housing portion 61 is locatedhigher than a bottom portion 62 a of the gear housing portion 62. Thepartition 61 c includes a partition opening 68 defined therein. Thepartition opening 68 is arranged to join the interior of the motorhousing portion 61 and the interior of the gear housing portion 62 toeach other. The partition 61 c is located on the left side of the stator30.

Oil O as a refrigerant is housed in the interior of the housing 6. Inthe present embodiment, the refrigerant is the oil O. In the presentpreferred embodiment, the oil O (refrigerant) is housed in the interiorof the motor housing portion 61 and the interior of the gear housingportion 62. An oil pool P, i.e., a pool of the oil O, is arranged in alower region in the interior of the gear housing portion 62. The oil Oin the oil pool P is sent to the interior of the motor housing portion61 through the oil passage 90. The oil O sent to the interior of themotor housing portion 61 is gathered in a lower region in the interiorof the motor housing portion 61. At least a portion of the oil Ogathered in the interior of the motor housing portion 61 travels intothe gear housing portion 62 through the partition opening 68 to returnto the oil pool P.

The oil O is arranged to circulate through the oil passage 90, whichwill be described below. The oil O functions not only for cooling themotor 2 but also for lubricating the gear portion 3. An oil equivalentto a lubricating oil (ATF: Automatic Transmission Fluid) for anautomatic transmission having a relatively low viscosity is preferablyused as the oil O so that the oil O can perform functions of alubricating oil and a cooling oil.

In the present preferred embodiment, the motor 2 is an inner-rotormotor. The motor 2 includes a rotor 20, the stator 30, and a pluralityof bearings 26 and 27. The rotor 20 is arranged to be capable ofrotating about the motor axis J1, which extends in the horizontaldirection. The rotor 20 includes a shaft 21 and a rotor body 24.Although not illustrated in the drawings, the rotor body 24 includes arotor core, and a rotor magnet fixed to the rotor core. A torque of therotor 20 is transferred to the gear portion 3.

The shaft 21 is arranged to extend in the axial direction with the motoraxis J1 as a center. The shaft 21 is arranged to rotate about the motoraxis J1. The shaft 21 is a hollow shaft including a hollow portion 22defined therein. The shaft 21 includes a communicating hole 23 definedtherein. The communicating hole 23 is arranged to extend in a radialdirection to join the hollow portion 22 to a space outside of the shaft21.

The shaft 21 is arranged to extend over the interior of the motorhousing portion 61 and the interior of the gear housing portion 62 ofthe housing 6. An end portion of the shaft 21 on the left side isarranged to project into the interior of the gear housing portion 62. Afirst gear 41, which will be described below, of the gear portion 3 isfixed to the end portion of the shaft 21 on the left side. The shaft 21is rotatably supported by the bearings 26 and 27.

The stator 30 is arranged radially opposite to the rotor 20 with a gaptherebetween. The stator 30 is located radially outside the rotor 20. Anouter peripheral surface of the stator 30 opposes an inner peripheralsurface of the housing 6. The stator 30 includes a stator core 32 and acoil assembly 33. The stator core 32 is fixed to an inner surface of themotor housing portion 61.

FIG. 2 is a perspective view illustrating the stator 30 and the supplypipe unit 10 located above the stator 30.

The stator core 32 includes a cylindrical core back portion 32 darranged to extend in the axial direction, and a plurality of toothportions 32 e arranged to extend radially inward from the core backportion 32 d. The plurality of tooth portions 32 e are arranged atintervals in the circumferential direction. The plurality of toothportions 32 e are arranged at regular intervals over the entirecircumference in the circumferential direction.

The core back portion 32 d has a plurality of fixing portions 32 bprojecting radially outward from an outer peripheral surface. The fixingportion 32 b is fixed to the inner surface of the motor housing portion61. That is, the stator 30 is fixed to the housing 6 at the fixingportion 32 b. A plurality of the fixing portions 32 b are provided atintervals in the circumferential direction. The number of fixingportions 32 b is, for example, four. The four fixing portions 32 b arearranged at regular intervals over the entire circumference in thecircumferential direction.

The fixing portion 32 b is arranged to extend along the axial direction.In the present embodiment, the fixing portion 32 b is arranged toextend, for example, from an end portion of the stator core 32 on theleft side (i.e., the +y side) to an end portion of the stator core 32 onthe right side (i.e., the −y side). That is, the fixing portion 32 b isarranged to extend over the entire length of the stator core 32 in theaxial direction.

The fixing portion 32 b includes a through hole 32 c arranged to passthrough the fixing portion 32 b in the axial direction. A bolt (notillustrated), which is arranged to extend in the axial direction, isinserted into the through hole 32 c. The bolt is arranged to passthrough the through hole 32 c from the right side (i.e., −y side) and isscrewed into a female screw hole (not illustrated) provided on the innersurface of the motor housing portion 61. As a result of the bolt beingscrewed into the female screw hole, the fixing portion 32 b is fixed tothe motor housing portion 61.

In the following description of the present specification, one of theplurality of (four in the present embodiment) fixing portions 32 bprojecting upward from the outer peripheral surface of the core backportion 32 d is referred to as an upper fixing portion 35. That is, oneof the plurality of fixing portions 32 b includes the upper fixingportion 35. Note that the other fixing portions 32 b project downward,forward (i.e., +x side), and backward (i.e., −x side), respectively.

Referring to FIG. 1, the coil assembly 33 includes a plurality of coils31 attached to the stator core 32. The plurality of coils 31 arerespectively mounted on the tooth portions 32 e of the stator core 32with an insulator (not illustrated) therebetween. The plurality of coils31 are arranged side by side in the circumferential direction. Theplurality of coils 31 are arranged at regular intervals over the entirecircumference in the circumferential direction. Although not illustratedin the drawings, the coil assembly 33 may include a binding member orthe like which is used to bind the coils 31 together, and may include apassage line arranged to join the coils 31 to one another.

The coil assembly 33 includes a pair of coil ends 33 a and 33 b each ofwhich is arranged to project in the axial direction from the stator core32. The coil end 33 a is a portion of the coil assembly 33 that projectsto the right side (i.e., −y side) from the stator core 32. The coil end33 b is a portion of the coil assembly 33 that projects to the left side(i.e., +y side) from the stator core 32. The coil end 33 a includes aportion of each of the coils 31 included in the coil assembly 33 whichprojects on the right side of the stator core 32. The coil end 33 bincludes a portion of each of the coils 31 included in the coil assembly33 which projects on the left side of the stator core 32.

Referring to FIG. 2, each of the coil ends 33 a and 33 b is in the shapeof a circular ring, and is centered on the motor axis J1 in the presentpreferred embodiment. Although not illustrated in the drawings, each ofthe coil ends 33 a and 33 b may include a binding member or the likewhich is used to bind the coils 31 together, and may include a passageline arranged to join the coils 31 to one another.

Referring to FIG. 1, the bearings 26 and 27 are arranged to rotatablysupport the rotor 20. Each of the bearings 26 and 27 is, for example, aball bearing. The bearing 26 is a bearing arranged to rotatably supporta portion of the rotor 20 which is located on the right side of thestator core 32. In the present preferred embodiment, the bearing 26 isarranged to support a portion of the shaft 21 which is located on theright side of a portion of the shaft 21 to which the rotor body 24 isfixed. The bearing 26 is held by a wall portion 61 b of the motorhousing portion 61 which covers the right side of the rotor 20 and thestator 30. The wall portion 61 b forms a part of the wall portion of thehousing 6 and closes an opening on the right side of the motor housingportion 61.

The bearing 27 is a bearing arranged to rotatably support a portion ofthe rotor 20 which is located on the left side of the stator core 32. Inthe present preferred embodiment, the bearing 27 is arranged to supporta portion of the shaft 21 which is located on the left side of theportion of the shaft 21 to which the rotor body 24 is fixed. The bearing27 is held by the partition 61 c.

The gear portion 3 is housed in the gear housing portion 62 of thehousing 6. The gear portion 3 is connected to the motor 2. In moredetail, the gear portion 3 is connected to the end portion of the shaft21 on the left side. The gear portion 3 includes the reduction gear 4and the differential 5. A torque outputted from the motor 2 istransferred to the differential 5 through the reduction gear 4.

The reduction gear 4 is connected to the motor 2. The reduction gear 4is arranged to increase the torque outputted from the motor 2 inaccordance with a reduction ratio while reducing the rotation speed ofthe motor 2. The reduction gear 4 is arranged to transfer the torqueoutputted from the motor 2 to the differential 5. The reduction gear 4includes the first gear 41, a second gear 42, a third gear 43, and anintermediate shaft 45.

The first gear 41 is fixed to an outer circumferential surface of theend portion of the shaft 21 on the left side. The first gear 41 isarranged to rotate about the motor axis J1 together with the shaft 21.The intermediate shaft 45 is arranged to extend along an intermediateaxis J2 parallel to the motor axis J1. The intermediate shaft 45 isarranged to rotate about the intermediate axis J2. The second gear 42and the third gear 43 are fixed to an outer peripheral surface of theintermediate shaft 45 at intervals in the axial direction. The secondgear 42 and the third gear 43 are connected to each other through theintermediate shaft 45. Each of the second gear 42 and the third gear 43is arranged to rotate about the intermediate axis J2. The second gear 42is arranged to mesh with the first gear 41. The third gear 43 isarranged to mesh with a ring gear 51, which will be described below, ofthe differential 5.

The torque outputted from the motor 2 is transferred to the ring gear 51of the differential 5 through, in order, the shaft 21, the first gear41, the second gear 42, the intermediate shaft 45, and the third gear43. The number of gears, the gear ratios of the gears, and the like canbe modified appropriately in accordance with a desired reduction ratio.In the present preferred embodiment, the reduction gear 4 is a speedreducer of a parallel-axis gearing type, in which center axes of gearsare arranged in parallel with each other.

The differential 5 is connected to the motor 2 through the reductiongear 4. The differential 5 is a device arranged to transfer the torqueoutputted from the motor 2 to wheels of the vehicle. The differential 5is arranged to transfer the same torque to axles 55 of left and rightwheels while absorbing a difference in speed between the left and rightwheels when the vehicle is turning. In this manner, the gear portion 3is arranged to transfer the torque of the motor 2 to the axles 55 of thevehicle through the reduction gear 4 and the differential 5 in thepresent preferred embodiment. The differential 5 includes the ring gear51, a gear housing (not shown), a pair of pinion gears (not shown), apinion shaft (not shown), and a pair of side gears (not shown). The ringgear 51 is arranged to rotate about a differential axis J3 parallel tothe motor axis J1. The torque outputted from the motor 2 is transferredto the ring gear 51 through the reduction gear 4.

The oil passage 90 is arranged to pass through the housing 6 andcirculate the oil O. The oil passage 90 is a channel of the oil O alongwhich the oil O is fed from the oil pool P to the gear portion 3 and themotor 2 and is led back to the oil pool P. The oil passage 90 isarranged to extend over both the interior of the motor housing portion61 and the interior of the gear housing portion 62.

Note that the term “oil passage” as used herein refers to a channel ofan oil. The concept of “oil passage” includes not only a “flow passage”,in which a steady flow of an oil in one direction is generated, but alsoa channel in which the oil is allowed to temporarily stay, and a channelalong which the oil drips. Examples of the channel in which the oil isallowed to temporarily stay include a reservoir arranged to store theoil.

The oil passage 90 includes a first oil passage 91 and a second oilpassage 92. Each of the first oil passage 91 and the second oil passage92 is arranged to circulate the oil O in the interior of the housing 6.

First, a common portion between the first oil passage 91 and the secondoil passage 92 will be described. Each of the first oil passage 91 andthe second oil passage 92 is a channel along which the oil O is fed fromthe oil pool P to the motor 2 and back into the oil pool P. In each ofthe first oil passage 91 and the second oil passage 92, the oil O dripsfrom the motor 2 to be gathered in a lower region of the motor housingportion 61. The oil O gathered in the lower region of the motor housingportion 61 is transferred to a lower region of the gear housing portion62 (i.e., the oil pool P) through the partition opening 68. That is, thefirst oil passage 91 and the second oil passage 92 include paths fortransferring the oil O from the lower region in the motor housingportion 61 to the lower region in the gear housing portion 62.

The first oil passage 91 includes a scraping-up channel 91 a, a shaftfeed channel 91 b, an intra-shaft channel 91 c, and an intra-rotorchannel 91 d. In addition, a reservoir 93 is arranged in the channel ofthe first oil passage 91. The reservoir 93 is arranged in the interiorof the gear housing portion 62.

The scraping-up channel 91 a is a channel along which the oil O isscraped up from the oil pool P by rotation of the ring gear 51 of thedifferential 5 to be received by the reservoir 93. The reservoir 93 isarranged to open upward. The reservoir 93 receives a portion of the oilO which has been scraped up by the ring gear 51. In addition, thereservoir 93 also receives portions of the oil O which have been scrapedup by the second gear 42 and the third gear 43 in addition to the ringgear 51 when, for example, a liquid surface S of the oil pool P is at ahigh level, e.g., immediately after the motor 2 is driven.

In the scraping-up channel 91 a, the oil O scraped up by the ring gear51 is fed to each gear of the gear portion 3 and spreads over a toothsurface of the gear. According to the present embodiment, the oilpassage 90 passes through the interior of the gear housing portion 62.As a result, the oil O can be used not only for cooling the motor 2 butalso for lubricating the respective gears and the respective bearings inthe gear portion 3.

The shaft feed channel 91 b is a channel arranged to lead the oil O fromthe reservoir 93 into the hollow portion 22 of the shaft 21. Theintra-shaft channel 91 c is a channel along which the oil O passes inthe hollow portion 22 of the shaft 21. The intra-rotor channel 91 d is achannel along which the oil O passes through the communicating hole 23of the shaft 21 and an interior of the rotor body 24, and is scatteredto the stator 30.

In the intra-shaft channel 91 c, a centrifugal force acts on the oil Oin the interior of the rotor 20 due to the rotation of the rotor 20.Thus, the oil O is continuously scattered radially outward from therotor 20. In addition, the scattering of the oil O generates a negativepressure in a channel in the interior of the rotor 20, causing the oil Ogathered in the reservoir 93 to be sucked into the interior of the rotor20, so that the channel in the interior of the rotor 20 is filled withthe oil O. A portion of the oil O which has reached the stator 30absorbs heat from the stator 30.

In the second oil passage 92, the oil O is lifted from the oil pool P,and is fed to the stator 30. The second oil passage 92 is provided withthe pump 96, the cooler 97, and the supply pipe unit 10. The second oilpassage 92 includes a first flow passage 92 a, a second flow passage 92b, a third flow passage 92 c, a fourth flow passage 94, a supply pipeinternal flow passage 92 d, and jet holes 14.

Each of the first flow passage 92 a, the second flow passage 92 b, thethird flow passage 92 c, and the fourth flow passage 94 is defined in awall portion of the housing 6. The first flow passage 92 a is arrangedto connect the oil pool P and the pump 96 to each other. The second flowpassage 92 b is arranged to connect the pump 96 and the cooler 97 toeach other. The third flow passage 92 c is arranged to join the cooler97 and the fourth flow passage 94 to each other. The third flow passage92 c is defined in, for example, a wall portion of the motor housingportion 61 on the forward side (i.e., the +x side).

The fourth flow passage 94 is provided in a wall portion or thepartition 61 c of the motor housing portion 61. The fourth flow passage94 is connected to the first supply pipe 11 and the second supply pipe12 of the supply pipe unit 10. That is, the fourth flow passage 94 isarranged to join the third flow passage 92 c and the supply pipe unit10. For example, the fourth flow passage 94 is arranged to extend in thehorizontal direction from a portion connected to the third flow passage92 c toward the rear side (i.e., −x side).

The supply pipe unit 10 is arranged between an inner peripheral surface61 a of the motor housing portion 61 and the outer peripheral surface ofthe stator 30. The supply pipe unit 10 is located above the stator 30.An end portion on the left side (i.e., +y side) of the supply pipe unit10 is fixed to the wall portion or the partition 61 c of the motorhousing portion 61. The end portion on the left side of the supply pipeunit 10 is connected to the fourth flow passage 94. An end portion onthe right side (i.e., −y side) of the supply pipe unit 10 is fixed to atop wall portion or the wall portion 61 b of the motor housing portion61. That is, the supply pipe unit 10 is fixed to the housing 6.

The supply pipe internal flow passage 92 d is a flow passage of therefrigerant arranged in the interior of the supply pipe unit 10. Morespecifically, the supply pipe internal flow passage 92 d is located ineach of the interior of the first supply pipe 11 and the interior of thesecond supply pipe 12 of the supply pipe unit 10. Therefore, the secondoil passage 92 is provided with the pair of supply pipe internal flowpassages 92 d. The supply pipe internal flow passage 92 d is arranged toextend in the axial direction. In addition, the pair of supply pipeinternal flow passages 92 d is connected to the fourth flow passage 94.

As illustrated in FIG. 2, the first supply pipe 11 and the second supplypipe 12 have a pipe shape extending in the axial direction. The firstsupply pipe 11 and the second supply pipe 12 are connected to each otherby a connecting portion 19 located at the end portion on the right side(i.e., −y side). That is, the supply pipe unit 10 includes the firstsupply pipe 11, the second supply pipe 12, and the connecting portion 19that connects the first supply pipe 11 and the second supply pipe 12. Inaddition, ribs for reinforcing the supply pipe unit 10 are providedbetween the first supply pipe 11 and the connecting portion 19 andbetween the second supply pipe 12 and the connecting portion 19.

The first supply pipe 11 and the second supply pipe 12 are cylindricalpipes arranged to extend linearly along the axial direction. The firstsupply pipe 11 and the second supply pipe 12 are arranged at intervalsin the front-rear direction. The first supply pipe 11 and the secondsupply pipe 12 are parallel to each other.

FIG. 3 is a partial cross-sectional view of the motor unit 1 includingthe supply pipe unit 10.

The first supply pipe 11 and the second supply pipe 12 are locatedradially outside the core back portion 32 d. In the present embodiment,a radial position of the first supply pipe 11 and a radial position ofthe second supply pipe 12 are the same. The first supply pipe 11 and thesecond supply pipe 12 are arranged above the core back portion 32 d. Avertical position of the first supply pipe 11 and a vertical position ofthe second supply pipe 12 are the same.

When viewed from the axial direction, the upper fixing portion 35 isarranged between the first supply pipe 11 and the second supply pipe 12.That is, the first supply pipe 11 and the second supply pipe 12 arearranged to extend along the axial direction on both side portions ofthe upper fixing portion 35 in the circumferential direction. Whenviewed from the axial direction, an imaginary straight line (notillustrated) passing through a central axis of the first supply pipe 11and a central axis of the second supply pipe 12 intersects with theupper fixing portion 35. The first supply pipe 11 and the second supplypipe 12 are located on the side portions of the upper fixing portion 35in the circumferential direction. In addition, the first supply pipe 11is located on one side of the upper fixing portion 35 in thecircumferential direction, and the second supply pipe 12 is located onthe other side of the upper fixing portion 35 in the circumferentialdirection.

FIG. 4 is a top view illustrating the stator and the supply pipe unit.

As illustrated in FIG. 4, positions of the first supply pipe 11, thesecond supply pipe 12, and the upper fixing portion 35 in the front-reardirection overlap each other. The first supply pipe 11 is located on thefront side (i.e., +x side) of the upper fixing portion 35, and thesecond supply pipe 12 is located on the rear side (i.e., −x side) of theupper fixing portion 35.

The first supply pipe 11 and the second supply pipe 12 have theplurality of jet holes 14 penetrating peripheral walls thereof. Asillustrated in FIG. 3, the jet holes 14 are arranged to extend in a piperadial direction perpendicular to the central axis of the first supplypipe 11 or the second supply pipe 12, and allows the interior and theoutside of the pipe to communicate. The jet hole 14 has, for example, acircular hole shape. The jet hole 14 is located between the innerperipheral surface of the housing 6 and the outer peripheral surface ofthe stator 30. The jet hole 14 jets the oil O flowing through the supplypipe internal flow passage 92 d to the motor 2.

As illustrated in FIG. 4, the plurality of jet holes 14 are arranged atintervals in the axial direction in the first supply pipe 11 and thesecond supply pipe 12. According to the present embodiment, the stator30 can be cooled in a wide range in the axial direction by the oil Ojetted from the plurality of jet holes 14 arranged in the axialdirection.

The jet holes 14 are classified into a plurality of first jet holes 14 aand a plurality of second jet holes 14 b. Each of the first supply pipe11 and the second supply pipe 12 has four first jet holes 14 a and twosecond jet holes 14 b.

In the first supply pipe 11 and the second supply pipe 12, the twosecond jet holes 14 b are arranged at both end portions, and the fourfirst jet holes 14 a are arranged side by side at regular intervals inthe axial direction between the two second jet holes 14 b.

Axial positions of the first jet hole 14 a overlap an axial position ofthe stator core 32. Similarly, axial positions of the second jet holes14 b overlap axial positions of the coil ends 33 a and 33 b. One of thetwo second jet holes 14 b located on the right side opposes the coil end33 a on the right side. Similarly, the other of the two second jet holes14 b located on the left side opposes the coil end 33 b on the leftside.

As illustrated in FIG. 3, the first jet hole 14 a is open toward theopposite side of the upper fixing portion 35 and downward in the firstsupply pipe 11 and the second supply pipe 12. That is, the first jethole 14 a is open toward an outer peripheral surface of the core backportion 32 d and a region opposite to the upper fixing portion 35. Forexample, regarding the region opposite to the upper fixing portion 35,an imaginary line VL connecting the first supply pipe 11 and the motoraxis J1 is assumed, and the first jet hole 14 a faces a region oppositeto a region where the upper fixing portion 35 is located with theimaginary line VL as a boundary. The first jet hole 14 a jets the oil Oto the outer peripheral surface of the core back portion 32 d. The oil Ojetted to the core back portion 32 d drips after cooling the core backportion 32 d while flowing along the outer peripheral surface of thecore back portion 32 d, and is gathered in the lower region in the motorhousing portion 61. According to the present embodiment, the first jethole 14 a is open toward the opposite side of the upper fixing portion35 and downward, the first jet hole 14 a is open to a region opposite tothe breather portion 70, so that it is possible to suppress the oil Ofrom leaking from the breather portion 70.

Note that the first jet hole 14 a may be open toward the motor axis J1as another embodiment.

As illustrated in FIG. 4, the second jet hole 14 b is open toward theopposite side of the upper fixing portion 35 and downward. The secondjet hole 14 b provided on the right side (i.e., −y side) between theplurality of second jet holes 14 b feeds the oil O to the coil end 33 aon the right side. Between the plurality of second jet holes 14 b, thesecond jet hole 14 b provided on the left side (i.e., +y side) jets theoil O to the coil end 33 b on the left side. The oil O jetted from thesecond jet hole 14 b is fed from the upper side to the coil ends 33 aand 33 b, cools the coil end 33 a, and then, drips to be gathered in thelower region in the motor housing portion 61.

Note that the first supply pipe 11 and the second supply pipe 12 servingas the supply portion have a pipe shape in the present embodiment, butthe present invention is not limited thereto, and for example, thesupply portion may have a gutter shape.

Next, a relative positional relationship between the first supply pipe11 and the second supply pipe 12 in the housing 6, and the breatherportion 70 will be described with reference to FIG. 3.

The housing 6 is provided with the breather portion 70. The breatherportion 70 allows the interior of the motor housing portion 61 and theoutside of the housing 6 to communicate and adjusts the internalpressure of the motor housing portion 61. More specifically, the oil Ois sealed in the housing 6 of the motor unit 1 in order to lubricate thereduction gear 4, the differential 5, and the respective bearings andcool the motor 2 by an axial oil feeding system or an oil bathlubrication system, and the breather portion 70 adjusts the internalpressure in the housing 6 so that the oil O does not leak from thehousing 6 when the internal pressure in the housing 6 increases due toan increase in temperature in the housing 6 during operation.

The breather portion 70 includes a vent portion 71 that allows theinterior and the outside of the motor housing portion 61 to communicate,and a pipe 72 attached to the vent portion 71. In the presentembodiment, the vent portion 71 is a circular hole. In addition, thevent portion 71 is arranged to extend linearly along the verticaldirection.

The pipe 72 is inserted into the vent portion 71. Both ends of the pipe72 are open and connect the interior of the vent portion 71 and theoutside of the housing 6. The pipe 72 has an L shape including a firstportion 72 a and a second portion 72 b bent with respect to the firstportion 72 a. The first portion 72 a is a portion inserted into the ventportion 71 from above. The first portion 72 a is arranged to extend inthe vertical direction around a central axis J4. The second portion 72 bis arranged to extend from an end portion on the upper side of the firstportion 72 a in a direction perpendicular to the vertical direction. Thesecond portion 72 b is located outside the housing 6. A hose (notillustrated) may be provided at a distal end portion of the secondportion 72 b. In addition, a filter may be provided at a distal end ofthe hose.

As illustrated in FIG. 4, the motor 2 is surrounded by the innerperipheral surface 61 a of the motor housing portion 61 from theradially outside. The inner peripheral surface 61 a of the motor housingportion 61 has a substantially circular shape centered on the motor axisJ1.

The inner peripheral surface 61 a of the motor housing portion 61 isprovided with a plurality of recessed portions 61 k in which the fixingportions 32 b are housed. The recessed portion 61 k is recessed radiallyoutward. In addition, the recessed portion 61 k is arranged to extendalong the axial direction. As described above, the core back portion 32d is provided with the four fixing portions 32 b. Therefore, the innerperipheral surface 61 a of the motor housing portion 61 is provided withfour recessed portions 61 k. A slight gap is provided between an innersurface of the recessed portion 61 k and an outer surface of the fixingportion 32 b housed in the recessed portion 61 k.

Here, the recessed portion 61 k that houses the upper fixing portion 35among the four recessed portions 61 k is referred to as an upperrecessed portion 65. The vent portion 71 of the breather portion 70 isopen in the upper recessed portion 65. In the present embodiment, arecess is further formed from an inner peripheral surface of the upperrecessed portion 65, and the opening of the vent portion 71 is formed ona bottom surface thereof. That is, the breather portion 70 is open intothe motor housing portion 61 in the upper recessed portion 65. Thebreather portion 70 is located above the upper fixing portion 35 housedin the upper recessed portion 65. The opening of the vent portion 71 islocated at the top (i.e., the highest portion) of the inner surface ofthe upper recessed portion 65.

As illustrated in FIG. 4, the breather portion 70 is arranged so as tooverlap the upper fixing portion 35 when viewed in the verticaldirection. That is, the breather portion 70 is located immediately abovethe upper fixing portion 35. In addition, an axial position of theopening of the breather portion 70 in the motor housing portion 61 issubstantially an intermediate position of the stator 30, and is arrangedto be shifted from the axial positions of the jet holes 14 of the firstsupply pipe 11 and the second supply pipe 12.

As illustrated in FIG. 3, the inner peripheral surface 61 a of the motorhousing portion 61 is provided with a supply pipe housing recessedportion 61 p in which the supply portion (the first supply pipe 11 orthe second supply pipe 12) is housed. The inner peripheral surface 61 aof the present embodiment is provided with two supply pipe housingrecessed portions 61 p corresponding to the two supply portions (thefirst supply pipe 11 and the second supply pipe 12). The two supply pipehousing recessed portions 61 p are arranged on both sides of the upperrecessed portion 65 in the circumferential direction. The first supplypipe 11 is housed in one of the two supply pipe housing recessedportions 61 p, and the second supply pipe 12 is housed in the other.

According to the present embodiment, the oil O in the motor housingportion 61 can suppress leakage of the oil from the breather portion 70even when the vehicle travels on a slope since the breather portion 70is located above the stator core 32. As a result, even when the vehicletravels on the slope, the breather portion 70 can appropriately adjustthe internal pressure in the motor housing portion 61.

Further, the breather portion 70 is located above the upper fixingportion 35 in the present embodiment. The upper fixing portion 35projects upward with respect to the outer peripheral surface of the coreback portion 32 d. Therefore, according to the present embodiment, theopening of the breather portion 70 can be separated from the channelthrough which the oil O flows, and the oil O can be prevented fromleaking from the breather portion 70.

In addition, the first supply pipe 11 and the second supply pipe 12 arelocated on the side portions of the upper fixing portion 35 in thecircumferential direction according to the present embodiment. The oil Osupplied from the first supply pipe 11 and the second supply pipe 12 tothe outer peripheral surface of the core back portion 32 d is blocked bythe upper fixing portion 35 and hardly reaches the opening of thebreather portion 70. As a result, the oil O can be prevented fromleaking from the breather portion 70.

According to the present embodiment, the supply portion that suppliesthe oil P to the motor 2 is the pipe-shaped supply pipe (the firstsupply pipe 11 and the second supply pipe 12) having the jet hole 14.Since the supply portion is formed into the pipe shape, the pressure ofthe oil O in the flow passage can be increased, and the flow velocity ofthe oil jetted from the jet hole 14 can be increased. As a result, theoil O can be scattered into a wide range from the jet hole 14, and awide range of the surface of the motor 2 can be cooled in awell-balanced manner.

According to the present embodiment, the first jet hole 14 a is opentoward the outer peripheral surface of the core back portion 32 d andthe region opposite to the upper fixing portion 35. That is, the oil Ojetted from the first jet hole 14 a is jetted toward the opposite sideof the breather portion 70. Therefore, the oil O jetted from the firstjet hole 14 a hardly enters the opening of the breather portion 70, andthe oil O can be prevented from leaking from the breather portion 70.

According to the present embodiment, the breather portion 70 is openinto the motor housing portion 61 in the upper recessed portion 65 inwhich the upper fixing portion 35 is housed. The oil O does not reachthe opening of the breather portion 70 unless the oil O passes throughthe gap between the inner surface of the upper recessed portion 65 andthe outer surface of the upper fixing portion 35. That is, according tothe present embodiment, the oil O hardly enters the opening of thebreather portion 70, and the leakage of the oil O from the breatherportion 70 can be suppressed.

According to the present embodiment, the opening of the breather portion70 in the motor housing portion 61 and the first jet hole 14 a arearranged at different positions in the axial direction. That is, itsuffices that the breather portion 70 is arranged at a position axiallydifferent from the jet holes arranged in one of the two supply portions(the first supply pipe 11 and the second supply pipe 12) in the presentembodiment. For example, the supply portion is a pipe having a pluralityof jet holes, and the breather portion is located within an axial lengthof the pipe. Further, the breather portion is arranged at a position notoverlapping any of the plurality of jet holes in the axial direction.Note that, in a case where the two supply portions are arranged, thebreather portion is preferably arranged at a position where the breatherportion does not overlap any of the plurality of jet holes located inthe two supply portions in the axial direction. Therefore, the oil Ojetted from the first jet hole 14 a hardly enters the opening of thebreather portion 70, and the oil O can be prevented from leaking fromthe breather portion 70. Note that, even in a case where a jet hole ofone of the two supply portions is at a position different from thebreather portion in the axial direction and a jet hole of the othersupply portion is at the same position as the breather portion in theaxial direction, it is possible to obtain a certain effect ofsuppressing leakage of oil from the breather portion.

According to the present embodiment, the two supply portions (the firstsupply pipe 11 and the second supply pipe 12) are located on the bothsides of the upper fixing portion 35 in the circumferential direction.Therefore, the oil O is supplied to the both sides in thecircumferential direction of the outer peripheral surface of the coreback portion 32 d with the upper fixing portion 35 as the center, andthe entire stator core 32 can be cooled in a balanced manner.

In addition, each configuration (constituent element) described in theabove-described embodiment, modifications, and the writings may becombined within the scope not departing from the spirit of the presentinvention, and addition, omission, replacement, and other changes of theconfiguration are possible. In addition, the present invention is notlimited by the above-described embodiment and the like, and is limitedonly by the scope of the claims.

Features of the above-described preferred embodiments and themodifications thereof may be combined appropriately as long as noconflict arises.

While preferred embodiments of the present disclosure have beendescribed above, it is to be understood that variations andmodifications will be apparent to those skilled in the art withoutdeparting from the scope and spirit of the present disclosure. The scopeof the present disclosure, therefore, is to be determined solely by thefollowing claims.

1. A motor unit comprising: a motor having a rotor that rotates about a motor axis and a stator located radially outside the rotor; a housing having a motor housing portion that houses the motor; and a refrigerant channel that is arranged to pass through an interior of the housing and circulate a refrigerant, wherein a core back portion of the stator has a plurality of fixing portions that are arranged to project radially outward from an outer peripheral surface and extend along an axial direction, and are fixed to the housing, the plurality of fixing portions include an upper fixing portion arranged to project upward from the outer peripheral surface of the core back portion, the refrigerant channel includes a supply portion that feeds the refrigerant to the outer peripheral surface of the core back portion, the supply portion is located on a side portion of the upper fixing portion in a circumferential direction, and the housing is provided with a breather portion that is located above the upper fixing portion and allows an interior of the motor housing portion and an outside of the housing to communicate.
 2. The motor unit according to claim 1, wherein the supply portion has a pipe shape extending along the axial direction on the side portion of the upper fixing portion in the circumferential direction, and has a jet hole for jetting the refrigerant on the outer peripheral surface of the core back portion.
 3. The motor unit according to claim 2, wherein the jet hole is open toward the outer peripheral surface of the core back portion and a region opposite to the upper fixing portion.
 4. The motor unit according to claim 2, wherein an opening of the breather portion in the motor housing portion and the jet hole are arranged at different positions in the axial direction.
 5. The motor unit according to claim 1, wherein the refrigerant channel includes the supply portion located on each of both sides of the upper fixing portion in the circumferential direction.
 6. The motor unit according to claim 1, wherein a recessed portion for housing the upper fixing portion is provided on an inner peripheral surface of the motor housing portion, and the breather portion is open into the motor housing in the recessed portion.
 7. The motor unit according to claim 1, wherein a supply pipe housing recessed portion for housing at least a part of the supply portion is provided on an inner peripheral surface of the motor housing portion.
 8. The motor unit according to claim 1, further comprising a gear portion connected to the motor, wherein the housing includes a gear housing portion that houses the gear portion, the refrigerant is oil, and the refrigerant channel is arranged to pass through an interior of the gear housing portion. 